arch/arm/mach-s3c64xx/dma.c

   1 /* linux/arch/arm/plat-s3c64xx/dma.c
   2  *
   3  * Copyright 2009 Openmoko, Inc.
   4  * Copyright 2009 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *      http://armlinux.simtec.co.uk/
   7  *
   8  * S3C64XX DMA core
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13 */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/dmapool.h>
  19 #include <linux/device.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/delay.h>
  23 #include <linux/clk.h>
  24 #include <linux/err.h>
  25 #include <linux/io.h>
  26 #include <linux/amba/pl080.h>
  27
  28 #include <mach/dma.h>
  29 #include <mach/map.h>
  30 #include <mach/irqs.h>
  31
  32 #include "regs-sys.h"
  33
  34 /* dma channel state information */
  35
  36 struct s3c64xx_dmac {
  37         struct device           dev;
  38         struct clk              *clk;
  39         void __iomem            *regs;
  40         struct s3c2410_dma_chan *channels;
  41         enum dma_ch              chanbase;
  42 };
  43
  44 /* pool to provide LLI buffers */
  45 static struct dma_pool *dma_pool;
  46
  47 /* Debug configuration and code */
  48
  49 static unsigned char debug_show_buffs = 0;
  50
  51 static void dbg_showchan(struct s3c2410_dma_chan *chan)
  52 {
  53         pr_debug("DMA%d: %08x->%08x L %08x C %08x,%08x S %08x\n",
  54                  chan->number,
  55                  readl(chan->regs + PL080_CH_SRC_ADDR),
  56                  readl(chan->regs + PL080_CH_DST_ADDR),
  57                  readl(chan->regs + PL080_CH_LLI),
  58                  readl(chan->regs + PL080_CH_CONTROL),
  59                  readl(chan->regs + PL080S_CH_CONTROL2),
  60                  readl(chan->regs + PL080S_CH_CONFIG));
  61 }
  62
  63 static void show_lli(struct pl080s_lli *lli)
  64 {
  65         pr_debug("LLI[%p] %08x->%08x, NL %08x C %08x,%08x\n",
  66                  lli, lli->src_addr, lli->dst_addr, lli->next_lli,
  67                  lli->control0, lli->control1);
  68 }
  69
  70 static void dbg_showbuffs(struct s3c2410_dma_chan *chan)
  71 {
  72         struct s3c64xx_dma_buff *ptr;
  73         struct s3c64xx_dma_buff *end;
  74
  75         pr_debug("DMA%d: buffs next %p, curr %p, end %p\n",
  76                  chan->number, chan->next, chan->curr, chan->end);
  77
  78         ptr = chan->next;
  79         end = chan->end;
  80
  81         if (debug_show_buffs) {
  82                 for (; ptr != NULL; ptr = ptr->next) {
  83                         pr_debug("DMA%d: %08x ",
  84                                  chan->number, ptr->lli_dma);
  85                         show_lli(ptr->lli);
  86                 }
  87         }
  88 }
  89
  90 /* End of Debug */
  91
  92 static struct s3c2410_dma_chan *s3c64xx_dma_map_channel(unsigned int channel)
  93 {
  94         struct s3c2410_dma_chan *chan;
  95         unsigned int start, offs;
  96
  97         start = 0;
  98
  99         if (channel >= DMACH_PCM1_TX)
 100                 start = 8;
 101
 102         for (offs = 0; offs < 8; offs++) {
 103                 chan = &s3c2410_chans[start + offs];
 104                 if (!chan->in_use)
 105                         goto found;
 106         }
 107
 108         return NULL;
 109
 110 found:
 111         s3c_dma_chan_map[channel] = chan;
 112         return chan;
 113 }
 114
 115 int s3c2410_dma_config(enum dma_ch channel, int xferunit)
 116 {
 117         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 118
 119         if (chan == NULL)
 120                 return -EINVAL;
 121
 122         switch (xferunit) {
 123         case 1:
 124                 chan->hw_width = 0;
 125                 break;
 126         case 2:
 127                 chan->hw_width = 1;
 128                 break;
 129         case 4:
 130                 chan->hw_width = 2;
 131                 break;
 132         default:
 133                 printk(KERN_ERR "%s: illegal width %d\n", __func__, xferunit);
 134                 return -EINVAL;
 135         }
 136
 137         return 0;
 138 }
 139 EXPORT_SYMBOL(s3c2410_dma_config);
 140
 141 static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan,
 142                                  struct pl080s_lli *lli,
 143                                  dma_addr_t data, int size)
 144 {
 145         dma_addr_t src, dst;
 146         u32 control0, control1;
 147
 148         switch (chan->source) {
 149         case DMA_FROM_DEVICE:
 150                 src = chan->dev_addr;
 151                 dst = data;
 152                 control0 = PL080_CONTROL_SRC_AHB2;
 153                 control0 |= PL080_CONTROL_DST_INCR;
 154                 break;
 155
 156         case DMA_TO_DEVICE:
 157                 src = data;
 158                 dst = chan->dev_addr;
 159                 control0 = PL080_CONTROL_DST_AHB2;
 160                 control0 |= PL080_CONTROL_SRC_INCR;
 161                 break;
 162         default:
 163                 BUG();
 164         }
 165
 166         /* note, we do not currently setup any of the burst controls */
 167
 168         control1 = size >> chan->hw_width;      /* size in no of xfers */
 169         control0 |= PL080_CONTROL_PROT_SYS;     /* always in priv. mode */
 170         control0 |= PL080_CONTROL_TC_IRQ_EN;    /* always fire IRQ */
 171         control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT;
 172         control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT;
 173
 174         lli->src_addr = src;
 175         lli->dst_addr = dst;
 176         lli->next_lli = 0;
 177         lli->control0 = control0;
 178         lli->control1 = control1;
 179 }
 180
 181 static void s3c64xx_lli_to_regs(struct s3c2410_dma_chan *chan,
 182                                 struct pl080s_lli *lli)
 183 {
 184         void __iomem *regs = chan->regs;
 185
 186         pr_debug("%s: LLI %p => regs\n", __func__, lli);
 187         show_lli(lli);
 188
 189         writel(lli->src_addr, regs + PL080_CH_SRC_ADDR);
 190         writel(lli->dst_addr, regs + PL080_CH_DST_ADDR);
 191         writel(lli->next_lli, regs + PL080_CH_LLI);
 192         writel(lli->control0, regs + PL080_CH_CONTROL);
 193         writel(lli->control1, regs + PL080S_CH_CONTROL2);
 194 }
 195
 196 static int s3c64xx_dma_start(struct s3c2410_dma_chan *chan)
 197 {
 198         struct s3c64xx_dmac *dmac = chan->dmac;
 199         u32 config;
 200         u32 bit = chan->bit;
 201
 202         dbg_showchan(chan);
 203
 204         pr_debug("%s: clearing interrupts\n", __func__);
 205
 206         /* clear interrupts */
 207         writel(bit, dmac->regs + PL080_TC_CLEAR);
 208         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 209
 210         pr_debug("%s: starting channel\n", __func__);
 211
 212         config = readl(chan->regs + PL080S_CH_CONFIG);
 213         config |= PL080_CONFIG_ENABLE;
 214         config &= ~PL080_CONFIG_HALT;
 215
 216         pr_debug("%s: writing config %08x\n", __func__, config);
 217         writel(config, chan->regs + PL080S_CH_CONFIG);
 218
 219         return 0;
 220 }
 221
 222 static int s3c64xx_dma_stop(struct s3c2410_dma_chan *chan)
 223 {
 224         u32 config;
 225         int timeout;
 226
 227         pr_debug("%s: stopping channel\n", __func__);
 228
 229         dbg_showchan(chan);
 230
 231         config = readl(chan->regs + PL080S_CH_CONFIG);
 232         config |= PL080_CONFIG_HALT;
 233         writel(config, chan->regs + PL080S_CH_CONFIG);
 234
 235         timeout = 1000;
 236         do {
 237                 config = readl(chan->regs + PL080S_CH_CONFIG);
 238                 pr_debug("%s: %d - config %08x\n", __func__, timeout, config);
 239                 if (config & PL080_CONFIG_ACTIVE)
 240                         udelay(10);
 241                 else
 242                         break;
 243                 } while (--timeout > 0);
 244
 245         if (config & PL080_CONFIG_ACTIVE) {
 246                 printk(KERN_ERR "%s: channel still active\n", __func__);
 247                 return -EFAULT;
 248         }
 249
 250         config = readl(chan->regs + PL080S_CH_CONFIG);
 251         config &= ~PL080_CONFIG_ENABLE;
 252         writel(config, chan->regs + PL080S_CH_CONFIG);
 253
 254         return 0;
 255 }
 256
 257 static inline void s3c64xx_dma_bufffdone(struct s3c2410_dma_chan *chan,
 258                                          struct s3c64xx_dma_buff *buf,
 259                                          enum s3c2410_dma_buffresult result)
 260 {
 261         if (chan->callback_fn != NULL)
 262                 (chan->callback_fn)(chan, buf->pw, 0, result);
 263 }
 264
 265 static void s3c64xx_dma_freebuff(struct s3c64xx_dma_buff *buff)
 266 {
 267         dma_pool_free(dma_pool, buff->lli, buff->lli_dma);
 268         kfree(buff);
 269 }
 270
 271 static int s3c64xx_dma_flush(struct s3c2410_dma_chan *chan)
 272 {
 273         struct s3c64xx_dma_buff *buff, *next;
 274         u32 config;
 275
 276         dbg_showchan(chan);
 277
 278         pr_debug("%s: flushing channel\n", __func__);
 279
 280         config = readl(chan->regs + PL080S_CH_CONFIG);
 281         config &= ~PL080_CONFIG_ENABLE;
 282         writel(config, chan->regs + PL080S_CH_CONFIG);
 283
 284         /* dump all the buffers associated with this channel */
 285
 286         for (buff = chan->curr; buff != NULL; buff = next) {
 287                 next = buff->next;
 288                 pr_debug("%s: buff %p (next %p)\n", __func__, buff, buff->next);
 289
 290                 s3c64xx_dma_bufffdone(chan, buff, S3C2410_RES_ABORT);
 291                 s3c64xx_dma_freebuff(buff);
 292         }
 293
 294         chan->curr = chan->next = chan->end = NULL;
 295
 296         return 0;
 297 }
 298
 299 int s3c2410_dma_ctrl(enum dma_ch channel, enum s3c2410_chan_op op)
 300 {
 301         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 302
 303         WARN_ON(!chan);
 304         if (!chan)
 305                 return -EINVAL;
 306
 307         switch (op) {
 308         case S3C2410_DMAOP_START:
 309                 return s3c64xx_dma_start(chan);
 310
 311         case S3C2410_DMAOP_STOP:
 312                 return s3c64xx_dma_stop(chan);
 313
 314         case S3C2410_DMAOP_FLUSH:
 315                 return s3c64xx_dma_flush(chan);
 316
 317         /* believe PAUSE/RESUME are no-ops */
 318         case S3C2410_DMAOP_PAUSE:
 319         case S3C2410_DMAOP_RESUME:
 320         case S3C2410_DMAOP_STARTED:
 321         case S3C2410_DMAOP_TIMEOUT:
 322                 return 0;
 323         }
 324
 325         return -ENOENT;
 326 }
 327 EXPORT_SYMBOL(s3c2410_dma_ctrl);
 328
 329 /* s3c2410_dma_enque
 330  *
 331  */
 332
 333 int s3c2410_dma_enqueue(enum dma_ch channel, void *id,
 334                         dma_addr_t data, int size)
 335 {
 336         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 337         struct s3c64xx_dma_buff *next;
 338         struct s3c64xx_dma_buff *buff;
 339         struct pl080s_lli *lli;
 340         unsigned long flags;
 341         int ret;
 342
 343         WARN_ON(!chan);
 344         if (!chan)
 345                 return -EINVAL;
 346
 347         buff = kzalloc(sizeof(struct s3c64xx_dma_buff), GFP_ATOMIC);
 348         if (!buff) {
 349                 printk(KERN_ERR "%s: no memory for buffer\n", __func__);
 350                 return -ENOMEM;
 351         }
 352
 353         lli = dma_pool_alloc(dma_pool, GFP_ATOMIC, &buff->lli_dma);
 354         if (!lli) {
 355                 printk(KERN_ERR "%s: no memory for lli\n", __func__);
 356                 ret = -ENOMEM;
 357                 goto err_buff;
 358         }
 359
 360         pr_debug("%s: buff %p, dp %08x lli (%p, %08x) %d\n",
 361                  __func__, buff, data, lli, (u32)buff->lli_dma, size);
 362
 363         buff->lli = lli;
 364         buff->pw = id;
 365
 366         s3c64xx_dma_fill_lli(chan, lli, data, size);
 367
 368         local_irq_save(flags);
 369
 370         if ((next = chan->next) != NULL) {
 371                 struct s3c64xx_dma_buff *end = chan->end;
 372                 struct pl080s_lli *endlli = end->lli;
 373
 374                 pr_debug("enquing onto channel\n");
 375
 376                 end->next = buff;
 377                 endlli->next_lli = buff->lli_dma;
 378
 379                 if (chan->flags & S3C2410_DMAF_CIRCULAR) {
 380                         struct s3c64xx_dma_buff *curr = chan->curr;
 381                         lli->next_lli = curr->lli_dma;
 382                 }
 383
 384                 if (next == chan->curr) {
 385                         writel(buff->lli_dma, chan->regs + PL080_CH_LLI);
 386                         chan->next = buff;
 387                 }
 388
 389                 show_lli(endlli);
 390                 chan->end = buff;
 391         } else {
 392                 pr_debug("enquing onto empty channel\n");
 393
 394                 chan->curr = buff;
 395                 chan->next = buff;
 396                 chan->end = buff;
 397
 398                 s3c64xx_lli_to_regs(chan, lli);
 399         }
 400
 401         local_irq_restore(flags);
 402
 403         show_lli(lli);
 404
 405         dbg_showchan(chan);
 406         dbg_showbuffs(chan);
 407         return 0;
 408
 409 err_buff:
 410         kfree(buff);
 411         return ret;
 412 }
 413
 414 EXPORT_SYMBOL(s3c2410_dma_enqueue);
 415
 416
 417 int s3c2410_dma_devconfig(enum dma_ch channel,
 418                           enum dma_data_direction source,
 419                           unsigned long devaddr)
 420 {
 421         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 422         u32 peripheral;
 423         u32 config = 0;
 424
 425         pr_debug("%s: channel %d, source %d, dev %08lx, chan %p\n",
 426                  __func__, channel, source, devaddr, chan);
 427
 428         WARN_ON(!chan);
 429         if (!chan)
 430                 return -EINVAL;
 431
 432         peripheral = (chan->peripheral & 0xf);
 433         chan->source = source;
 434         chan->dev_addr = devaddr;
 435
 436         pr_debug("%s: peripheral %d\n", __func__, peripheral);
 437
 438         switch (source) {
 439         case DMA_FROM_DEVICE:
 440                 config = 2 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 441                 config |= peripheral << PL080_CONFIG_SRC_SEL_SHIFT;
 442                 break;
 443         case DMA_TO_DEVICE:
 444                 config = 1 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
 445                 config |= peripheral << PL080_CONFIG_DST_SEL_SHIFT;
 446                 break;
 447         default:
 448                 printk(KERN_ERR "%s: bad source\n", __func__);
 449                 return -EINVAL;
 450         }
 451
 452         /* allow TC and ERR interrupts */
 453         config |= PL080_CONFIG_TC_IRQ_MASK;
 454         config |= PL080_CONFIG_ERR_IRQ_MASK;
 455
 456         pr_debug("%s: config %08x\n", __func__, config);
 457
 458         writel(config, chan->regs + PL080S_CH_CONFIG);
 459
 460         return 0;
 461 }
 462 EXPORT_SYMBOL(s3c2410_dma_devconfig);
 463
 464
 465 int s3c2410_dma_getposition(enum dma_ch channel,
 466                             dma_addr_t *src, dma_addr_t *dst)
 467 {
 468         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 469
 470         WARN_ON(!chan);
 471         if (!chan)
 472                 return -EINVAL;
 473
 474         if (src != NULL)
 475                 *src = readl(chan->regs + PL080_CH_SRC_ADDR);
 476
 477         if (dst != NULL)
 478                 *dst = readl(chan->regs + PL080_CH_DST_ADDR);
 479
 480         return 0;
 481 }
 482 EXPORT_SYMBOL(s3c2410_dma_getposition);
 483
 484 /* s3c2410_request_dma
 485  *
 486  * get control of an dma channel
 487 */
 488
 489 int s3c2410_dma_request(enum dma_ch channel,
 490                         struct s3c2410_dma_client *client,
 491                         void *dev)
 492 {
 493         struct s3c2410_dma_chan *chan;
 494         unsigned long flags;
 495
 496         pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
 497                  channel, client->name, dev);
 498
 499         local_irq_save(flags);
 500
 501         chan = s3c64xx_dma_map_channel(channel);
 502         if (chan == NULL) {
 503                 local_irq_restore(flags);
 504                 return -EBUSY;
 505         }
 506
 507         dbg_showchan(chan);
 508
 509         chan->client = client;
 510         chan->in_use = 1;
 511         chan->peripheral = channel;
 512         chan->flags = 0;
 513
 514         local_irq_restore(flags);
 515
 516         /* need to setup */
 517
 518         pr_debug("%s: channel initialised, %p\n", __func__, chan);
 519
 520         return chan->number | DMACH_LOW_LEVEL;
 521 }
 522
 523 EXPORT_SYMBOL(s3c2410_dma_request);
 524
 525 /* s3c2410_dma_free
 526  *
 527  * release the given channel back to the system, will stop and flush
 528  * any outstanding transfers, and ensure the channel is ready for the
 529  * next claimant.
 530  *
 531  * Note, although a warning is currently printed if the freeing client
 532  * info is not the same as the registrant's client info, the free is still
 533  * allowed to go through.
 534 */
 535
 536 int s3c2410_dma_free(enum dma_ch channel, struct s3c2410_dma_client *client)
 537 {
 538         struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
 539         unsigned long flags;
 540
 541         if (chan == NULL)
 542                 return -EINVAL;
 543
 544         local_irq_save(flags);
 545
 546         if (chan->client != client) {
 547                 printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n",
 548                        channel, chan->client, client);
 549         }
 550
 551         /* sort out stopping and freeing the channel */
 552
 553
 554         chan->client = NULL;
 555         chan->in_use = 0;
 556
 557         if (!(channel & DMACH_LOW_LEVEL))
 558                 s3c_dma_chan_map[channel] = NULL;
 559
 560         local_irq_restore(flags);
 561
 562         return 0;
 563 }
 564
 565 EXPORT_SYMBOL(s3c2410_dma_free);
 566
 567 static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
 568 {
 569         struct s3c64xx_dmac *dmac = pw;
 570         struct s3c2410_dma_chan *chan;
 571         enum s3c2410_dma_buffresult res;
 572         u32 tcstat, errstat;
 573         u32 bit;
 574         int offs;
 575
 576         tcstat = readl(dmac->regs + PL080_TC_STATUS);
 577         errstat = readl(dmac->regs + PL080_ERR_STATUS);
 578
 579         for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
 580                 struct s3c64xx_dma_buff *buff;
 581
 582                 if (!(errstat & bit) && !(tcstat & bit))
 583                         continue;
 584
 585                 chan = dmac->channels + offs;
 586                 res = S3C2410_RES_ERR;
 587
 588                 if (tcstat & bit) {
 589                         writel(bit, dmac->regs + PL080_TC_CLEAR);
 590                         res = S3C2410_RES_OK;
 591                 }
 592
 593                 if (errstat & bit)
 594                         writel(bit, dmac->regs + PL080_ERR_CLEAR);
 595
 596                 /* 'next' points to the buffer that is next to the
 597                  * currently active buffer.
 598                  * For CIRCULAR queues, 'next' will be same as 'curr'
 599                  * when 'end' is the active buffer.
 600                  */
 601                 buff = chan->curr;
 602                 while (buff && buff != chan->next
 603                                 && buff->next != chan->next)
 604                         buff = buff->next;
 605
 606                 if (!buff)
 607                         BUG();
 608
 609                 if (buff == chan->next)
 610                         buff = chan->end;
 611
 612                 s3c64xx_dma_bufffdone(chan, buff, res);
 613
 614                 /* Free the node and update curr, if non-circular queue */
 615                 if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) {
 616                         chan->curr = buff->next;
 617                         s3c64xx_dma_freebuff(buff);
 618                 }
 619
 620                 /* Update 'next' */
 621                 buff = chan->next;
 622                 if (chan->next == chan->end) {
 623                         chan->next = chan->curr;
 624                         if (!(chan->flags & S3C2410_DMAF_CIRCULAR))
 625                                 chan->end = NULL;
 626                 } else {
 627                         chan->next = buff->next;
 628                 }
 629         }
 630
 631         return IRQ_HANDLED;
 632 }
 633
 634 static struct bus_type dma_subsys = {
 635         .name           = "s3c64xx-dma",
 636         .dev_name       = "s3c64xx-dma",
 637 };
 638
 639 static int s3c64xx_dma_init1(int chno, enum dma_ch chbase,
 640                              int irq, unsigned int base)
 641 {
 642         struct s3c2410_dma_chan *chptr = &s3c2410_chans[chno];
 643         struct s3c64xx_dmac *dmac;
 644         char clkname[16];
 645         void __iomem *regs;
 646         void __iomem *regptr;
 647         int err, ch;
 648
 649         dmac = kzalloc(sizeof(struct s3c64xx_dmac), GFP_KERNEL);
 650         if (!dmac) {
 651                 printk(KERN_ERR "%s: failed to alloc mem\n", __func__);
 652                 return -ENOMEM;
 653         }
 654
 655         dmac->dev.id = chno / 8;
 656         dmac->dev.bus = &dma_subsys;
 657
 658         err = device_register(&dmac->dev);
 659         if (err) {
 660                 printk(KERN_ERR "%s: failed to register device\n", __func__);
 661                 goto err_alloc;
 662         }
 663
 664         regs = ioremap(base, 0x200);
 665         if (!regs) {
 666                 printk(KERN_ERR "%s: failed to ioremap()\n", __func__);
 667                 err = -ENXIO;
 668                 goto err_dev;
 669         }
 670
 671         snprintf(clkname, sizeof(clkname), "dma%d", dmac->dev.id);
 672
 673         dmac->clk = clk_get(NULL, clkname);
 674         if (IS_ERR(dmac->clk)) {
 675                 printk(KERN_ERR "%s: failed to get clock %s\n", __func__, clkname);
 676                 err = PTR_ERR(dmac->clk);
 677                 goto err_map;
 678         }
 679
 680         clk_enable(dmac->clk);
 681
 682         dmac->regs = regs;
 683         dmac->chanbase = chbase;
 684         dmac->channels = chptr;
 685
 686         err = request_irq(irq, s3c64xx_dma_irq, 0, "DMA", dmac);
 687         if (err < 0) {
 688                 printk(KERN_ERR "%s: failed to get irq\n", __func__);
 689                 goto err_clk;
 690         }
 691
 692         regptr = regs + PL080_Cx_BASE(0);
 693
 694         for (ch = 0; ch < 8; ch++, chptr++) {
 695                 pr_debug("%s: registering DMA %d (%p)\n",
 696                          __func__, chno + ch, regptr);
 697
 698                 chptr->bit = 1 << ch;
 699                 chptr->number = chno + ch;
 700                 chptr->dmac = dmac;
 701                 chptr->regs = regptr;
 702                 regptr += PL080_Cx_STRIDE;
 703         }
 704
 705         /* for the moment, permanently enable the controller */
 706         writel(PL080_CONFIG_ENABLE, regs + PL080_CONFIG);
 707
 708         printk(KERN_INFO "PL080: IRQ %d, at %p, channels %d..%d\n",
 709                irq, regs, chno, chno+8);
 710
 711         return 0;
 712
 713 err_clk:
 714         clk_disable(dmac->clk);
 715         clk_put(dmac->clk);
 716 err_map:
 717         iounmap(regs);
 718 err_dev:
 719         device_unregister(&dmac->dev);
 720 err_alloc:
 721         kfree(dmac);
 722         return err;
 723 }
 724
 725 static int __init s3c64xx_dma_init(void)
 726 {
 727         int ret;
 728
 729         printk(KERN_INFO "%s: Registering DMA channels\n", __func__);
 730
 731         dma_pool = dma_pool_create("DMA-LLI", NULL, sizeof(struct pl080s_lli), 16, 0);
 732         if (!dma_pool) {
 733                 printk(KERN_ERR "%s: failed to create pool\n", __func__);
 734                 return -ENOMEM;
 735         }
 736
 737         ret = subsys_system_register(&dma_subsys, NULL);
 738         if (ret) {
 739                 printk(KERN_ERR "%s: failed to create subsys\n", __func__);
 740                 return -ENOMEM;
 741         }
 742
 743         /* Set all DMA configuration to be DMA, not SDMA */
 744         writel(0xffffff, S3C64XX_SDMA_SEL);
 745
 746         /* Register standard DMA controllers */
 747         s3c64xx_dma_init1(0, DMACH_UART0, IRQ_DMA0, 0x75000000);
 748         s3c64xx_dma_init1(8, DMACH_PCM1_TX, IRQ_DMA1, 0x75100000);
 749
 750         return 0;
 751 }
 752
 753 arch_initcall(s3c64xx_dma_init);